MICROSOFT-EXCHANGE
This signature detects Messaging Application Programming Interface (MAPI), which is a proprietary to Microsoft implemented using Microsoft's MSRPC strain of the DCE/RPC protocol. Microsoft Outlook uses it to communicate with Microsoft Exchange.
Available to all SRX running 12.3X48+
Available to all MX running 20.2R1+
Available to all vSRX running 20.3R1+